1. FIELD OF THE INVENTION
The present invention relates to a belt type continuously variable transmission incorporated in a power transmitting system of a vehicle such as motorcycles and automobiles, and particularly, a belt type continuously variable transmission comprising an input shaft driven from an engine, an output shaft for driving a wheel, a drive V-pulley mounted on the input shaft and variable in effective radius, a driven V-pulley mounted on the output shaft and variable in effective radius, a V-belt stretched around the both pulleys, a hydraulic actuator for changing the effective radius of each of the V-pulleys, and a hydraulic pressure controller for controlling the hydraulic pressure supplied to the hydraulic actuator, the controller being provided between the hydraulic actuator and a hydraulic pump driven by the engine to supply a hydraulic pressure to the hydraulic actuator.
2. DESCRIPTION OF THE PRIOR ART
In such belt type continuously variable transmission, a high hydraulic pressure constantly applied to the hydraulic actuator results not only in an increased burden on the hydraulic pump to bring about a loss of power of the engine, but also in an excessive tension applied to the V-belt to reduce the life thereof.